There’s no word yet on what kind of character Slattery will play, but his role will span multiple episodes. Though his character on Mad Men is straight-laced when compared to the cast he’ll be joining on Arrested Development, Slattery is no stranger to comedic acting. He has appeared on 30 Rock, SNL and had a reoccurring role on the TV series Ed in the early ‘00s.

Arrested Development’s ten-episode fourth season is expected to be released on Netflix sometime in 2013.